The authors had studied the interactions between implant defects and P diffusion in crystalline silicon. Defect engineering enables ultra-shallow n+/p junction formation using phosphorus, carbon, and Ge co-implants, and spike anneal. Their experimental data suggested that the positioning of a pre-amorphized layer using Ge implants plays an important role in P diffusion. They find that extending the overlap of Ge pre-amorphization and C profiles results in greater reduction of P transient-enhanced diffusion by trapping more excess interstitials. This conclusion was consistent with the end-of-range defects calculated by Monte Carlo simulation and annealed C profiles.

Effects of Germanium and Carbon Co-Implants on Phosphorus Diffusion in Silicon. K.C.Ku, C.F.Nieh, J.Gong, L.P.Huang, Y.M.Sheu, C.C.Wang, C.H.Chen, H.Chang, L.T.Wang, T.L.Lee, S.C.Chen, M.S.Liang: Applied Physics Letters, 2006, 89[11], 112104 (3pp)